<?php
//ctype_upper(mixed $text): bool
//ctype_upper — 检测大写字符
$aa = 'AKLWC139';
$bb = 'LMNSDO';
$cc = 'akwSKWsm';
if (ctype_upper($aa)) {
    echo '$aa ' . "ok" . PHP_EOL;
} else {
    echo '$aa ' . "no" . PHP_EOL;

}

if (ctype_upper($bb)) {
    echo '$bb ' . "ok" . PHP_EOL;
} else {
    echo '$bb ' . "no" . PHP_EOL;

}
if (ctype_upper($cc)) {
    echo '$cc ' . "ok" . PHP_EOL;
} else {
    echo '$cc ' . "no" . PHP_EOL;

}
